Question: If $x \diamond y = x-3y$ and $x \veebar y = 3x-4y$, find $3 \veebar (6 \diamond 3)$.
Explanation: First, find $6 \diamond 3$ $ 6 \diamond 3 = 6-(3)(3)$ $ \hphantom{6 \diamond 3} = -3$ Now, find $3 \veebar -3$ $ 3 \veebar -3 = (3)(3)-(4)(-3)$ $ \hphantom{3 \veebar -3} = 21$.